Add --no-partial-obsrvations to FreeBayes
Add --no-partial-obsrvations to FreeBayes

Improves discrimination of heterozygote/homozygote calls:
https://github.com/ekg/freebayes/issues/234#issuecomment-205331765

lbeltrame/bcbio-nextgen,a113n/bcbio-nextgen,biocyberman/bcbio-nextgen,biocyberman/bcbio-nextgen,brainstorm/bcbio-nextgen,vladsaveliev/bcbio-nextgen,lbeltrame/bcbio-nextgen,chapmanb/bcbio-nextgen,mjafin/bcbio-nextgen,a113n/bcbio-nextgen,mjafin/bcbio-nextgen,mjafin/bcbio-nextgen,lbeltrame/bcbio-nextgen,biocyberman/bcbio-nextgen,vladsaveliev/bcbio-nextgen,brainstorm/bcbio-nextgen,chapmanb/bcbio-nextgen,brainstorm/bcbio-nextgen,a113n/bcbio-nextgen,vladsaveliev/bcbio-nextgen,chapmanb/bcbio-nextgen